11 #include "snapshot.h"
16  * Snapshot trees:
18  * Keys in BTREE_ID_snapshot_trees identify a whole tree of snapshot nodes; they
19  * exist to provide a stable identifier for the whole lifetime of a snapshot
28 	prt_printf(out, "subvol %u root snapshot %u",  in bch2_snapshot_tree_to_text()
92 /* Snapshot nodes: */
345 				       BTREE_ITER_WITH_UPDATES, snapshot, s);  in bch2_snapshot_lookup()
358 		bch_err(trans->c, "snapshot node %u not found", id);  in bch2_snapshot_live()
366  * If @k is a snapshot with just one live child, it's part of a linear chain,
367  * which we consider to be an equivalence class: and then after snapshot
479 		if (!bch2_snapshot_is_ancestor(c, le32_to_cpu(s.v->snapshot), snapshot_root))  in bch2_snapshot_tree_master_subvol()
534 			"snapshot tree points to missing/incorrect snapshot:\n  %s",  in check_snapshot_tree()
547 			"snapshot tree points to missing subvolume:\n  %s",  in check_snapshot_tree()
551 						le32_to_cpu(subvol.snapshot),  in check_snapshot_tree()
554 			"snapshot tree points to subvolume that does not point to snapshot in this tree:\n  %s",  in check_snapshot_tree()
559 			"snapshot tree points to snapshot subvolume:\n  %s",  in check_snapshot_tree()
584  * For each snapshot_tree, make sure it points to the root of a snapshot tree
585  * and that snapshot entry points back to it, or delete it.
587  * And, make sure it points to a subvolume within that snapshot tree, or correct
588  * it to point to the oldest subvolume within that snapshot tree.
603  * Look up snapshot tree for @tree_id and find root,
653  * snapshot_tree pointer was incorrect: look up root snapshot node, make sure
672 			       BTREE_ITER_WITH_UPDATES, snapshot);  in snapshot_tree_ptr_repair()
684 		u = bch2_bkey_make_mut_typed(trans, &root_iter, &root.s_c, 0, snapshot);  in snapshot_tree_ptr_repair()
698 		u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);  in snapshot_tree_ptr_repair()
737 			bch_err(c, "snapshot with nonexistent parent:\n  %s",  in check_snapshot()
744 			bch_err(c, "snapshot parent %u missing pointer to child %llu",  in check_snapshot()
756 			bch_err(c, "snapshot node %llu has nonexistent child %u",  in check_snapshot()
762 			bch_err(c, "snapshot child %u has wrong parent (got %u should be %llu)",  in check_snapshot()
776 			bch_err(c, "snapshot points to nonexistent subvolume:\n  %s",  in check_snapshot()
781 		if (BCH_SNAPSHOT_SUBVOL(&s) != (le32_to_cpu(subvol.snapshot) == k.k->p.offset)) {  in check_snapshot()
782 			bch_err(c, "snapshot node %llu has wrong BCH_SNAPSHOT_SUBVOL",  in check_snapshot()
790 				"snapshot should not point to subvol:\n  %s",  in check_snapshot()
792 			u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);  in check_snapshot()
807 			"snapshot points to missing/incorrect tree:\n  %s",  in check_snapshot()
819 			"snapshot with incorrect depth field, should be %u:\n  %s",  in check_snapshot()
821 		u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);  in check_snapshot()
835 			"snapshot with bad skiplist field:\n  %s",  in check_snapshot()
837 		u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);  in check_snapshot()
872  * Mark a snapshot as deleted, for future cleanup:
882 				    0, snapshot);  in bch2_snapshot_node_set_deleted()
886 					trans->c, "missing snapshot %u", id);  in bch2_snapshot_node_set_deleted()
920 				     BTREE_ITER_INTENT, snapshot);  in bch2_snapshot_node_delete()
923 				"missing snapshot %u", id);  in bch2_snapshot_node_delete()
938 				     0, snapshot);  in bch2_snapshot_node_delete()
941 					"missing snapshot %u", parent_id);  in bch2_snapshot_node_delete()
951 					"snapshot %u missing child pointer to %u",  in bch2_snapshot_node_delete()
965 				     0, snapshot);  in bch2_snapshot_node_delete()
968 					"missing snapshot %u", child_id);  in bch2_snapshot_node_delete()
983 		 * We're deleting the root of a snapshot tree: update the  in bch2_snapshot_node_delete()
985 		 * this is the last snapshot ID in this tree:  in bch2_snapshot_node_delete()
1046 		n = bch2_bkey_alloc(trans, &iter, 0, snapshot);  in create_snapids()
1082  * Create new snapshot IDs as children of an existing snapshot ID:
1095 			0, snapshot);  in bch2_snapshot_node_create_children()
1099 			bch_err(trans->c, "snapshot %u not found", parent);  in bch2_snapshot_node_create_children()
1104 		bch_err(trans->c, "Trying to add child snapshot nodes to parent that already has children");  in bch2_snapshot_node_create_children()
1124  * Create a snapshot node that is the root of a new tree:
1163  * If we have an unlinked inode in an internal snapshot node, and the inode
1170  * also: unlinked inode in internal snapshot appears to not be getting deleted
1175  * for a key in an interior snapshot node that needs work to be done that
1177  * that key to snapshot leaf nodes, where we can mutate it
1188 	u32 equiv = bch2_snapshot_equiv(c, k.k->p.snapshot);  in snapshot_delete_key()
1194 	if (snapshot_list_has_id(deleted, k.k->p.snapshot) ||  in snapshot_delete_key()
1208 	u32 equiv = bch2_snapshot_equiv(c, k.k->p.snapshot);  in move_key_to_correct_snapshot()
1211 	 * When we have a linear chain of snapshot nodes, we consider  in move_key_to_correct_snapshot()
1218 	 * snapshot - the rest have been overwritten and are redundant,  in move_key_to_correct_snapshot()
1222 	if (equiv != k.k->p.snapshot) {  in move_key_to_correct_snapshot()
1231 		new->k.p.snapshot = equiv;  in move_key_to_correct_snapshot()
1276  * For a given snapshot, if it doesn't have a subvolume that points to it, and
1277  * it doesn't have child snapshot nodes - it's now redundant and we can mark it
1321 	s = bch2_bkey_make_mut_noupdate_typed(trans, k, snapshot);  in bch2_fix_child_of_deleted_snapshot()
1383 	 * For every snapshot node: If we have no live children and it's not  in bch2_delete_dead_snapshots()
1455 		u32 snapshot = k.k->p.offset;  in bch2_delete_dead_snapshots()
1456 		u32 equiv = bch2_snapshot_equiv(c, snapshot);  in bch2_delete_dead_snapshots()
1458 		equiv != snapshot  in bch2_delete_dead_snapshots()
1459 			? snapshot_list_add(c, &deleted_interior, snapshot)  in bch2_delete_dead_snapshots()
1482 		bch_err_msg(c, ret, "deleting snapshot %u", *i);  in bch2_delete_dead_snapshots()
1490 		bch_err_msg(c, ret, "deleting snapshot %u", *i);  in bch2_delete_dead_snapshots()
1543 		if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, pos.snapshot)) {  in __bch2_key_has_snapshot_overwrites()
1580 	pos.snapshot = leaf_id;  in bch2_propagate_key_to_snapshot_leaf()
1588 	/* key already overwritten in this snapshot? */  in bch2_propagate_key_to_snapshot_leaf()
1589 	if (k.k->p.snapshot != interior_k.k->p.snapshot)  in bch2_propagate_key_to_snapshot_leaf()
1594 		new_min_pos->snapshot = leaf_id;  in bch2_propagate_key_to_snapshot_leaf()
1602 	new->k.p.snapshot = leaf_id;  in bch2_propagate_key_to_snapshot_leaf()
1625 	for (u32 id = bch2_snapshot_smallest_descendent(c, k.k->p.snapshot);  in bch2_propagate_key_to_snapshot_leaves()
1626 	     id < k.k->p.snapshot;  in bch2_propagate_key_to_snapshot_leaves()
1628 		if (!bch2_snapshot_is_ancestor(c, id, k.k->p.snapshot) ||  in bch2_propagate_key_to_snapshot_leaves()